The court battle over Proposition 8 has escalated yet another step—now over a First Amendment issue.

Two days after attorneys for proponents of California’s ban on same-sex marriage filed a motion seeking to have a videotape of the landmark Proposition 8 trial sequestered from public availability, attorneys for same-sex couples challenging the ban filed a motion seeking the tape’s “immediate release.”

Attorneys for the City of San Francisco and attorneys for a coalition of media organizations covering the case are also expected to file requests this week for immediate release of the tape.

This is just the latest round in an almost two-year-old court battle between attorneys for Yes on 8, which campaigned for passage of Proposition 8, and attorneys for the American Foundation for Equal Rights (AFER), which organized the so-far successful lawsuit against it. Ted Olson, David Boies, and Theodore Boutrous are the lead attorneys for AFER’s case.

The Olson-Boies team submitted a brief to the 9th Circuit U.S. Court of Appeals April 15 saying the request by Yes on 8 to “sequester and forever conceal” the videotape of the January 2010 trial against Proposition 8 “directly conflicts with this Nation’s constitutional commitment to public and open judicial process and serves no legitimate public end.”

The First Amendment, they argue, “guarantees free and open access to judicial proceedings in order to foster public confidence in the judicial system.”

The First Amendment question is now the fourth issue before the 9th Circuit in the Proposition 8 case, Perry v. Brown. (Under Governor Arnold Schwarzenegger, the case was known as Perry v. Schwarzenegger. Governor Jerry Brown took office in January of this year, so the case is now known as Perry v. Brown.) The other questions include whether Proposition 8 violates the equal protection and due process guarantees of the U.S. Constitution, and whether Yes on 8 has legal standing to bring an appeal of the district court ruling to the appeals court.

Yes on 8 attorneys filed their motion April 13 with the 9th Circuit, claiming that former U.S. District Court Chief Judge Vaughn Walker—who presided over last year’s trial—“defied” a U.S. Supreme Court decision in February of this year when he showed a college audience a video clip from the January 2010 trial.

Walker played a three-minute clip from the video recording of the trial, saying he wanted to illustrate to an audience of journalists and lawyers that actual court proceedings can be tedious for lay viewers because they can be fraught with long pauses and abstruse colloquies between lawyers and judges.

Yes on 8 attorneys, led by Charles Cooper, Anthony Pugno, and Alliance Defense Fund’s James Campbell, said Walker’s use of the clip violated an order from the U.S. Supreme Court and a policy of the 9th Circuit against broadcast of district court trial proceedings.

The Olson team’s brief countered, saying a 1982 U.S. Supreme Court ruling (Globe v. Superior Court) held that “public access to trials ‘protect[s] the free discussion of governmental affairs’ that is essential to the ability of ‘the individual citizen . . . [to] effectively participate in and contribute to our republican system of self-government’.” (In Globe, the Supreme Court ruled against a Massachusetts court order that had closed to the public and the press the trial of a man accused of raping three minor children.)

Judge Walker, who is now retired from the bench, ruled in August 2010 that Proposition 8, which was added to the California constitution by voters during a November 2008 initiative, violates the equal protection and due process guarantees of the federal constitution. The 9th Circuit put a stay on that ruling until it can rule on the appeal. But the 9th Circuit has delayed ruling on the federal constitutional questions until it gets a ruling from the California Supreme Court on whether there is any authority in state law that enables Yes on 8 to appeal the Perry decision even though the state’s governor and attorney general declined to appeal it.

The California Supreme Court is expected to hear oral argument on the standing question in September.